| 摘要 |
PROBLEM TO BE SOLVED: To reduce shift shock in a gear change range converting time, as well as to secure the forward running even though a passage converting means for forward running is made impossible to convert when a forward running range is selected. SOLUTION: A changeover valve 220 converts an oil passage connected to an advance clutch 27, while a change-over valve 230 converts an oil passage connected to the rearward running brake 28. The oil passages of the change-over valves 220 and 230 are converted by a control pressure applied from a solenoid valve 210. The change-over valve 220 has a normal oil passage 221, and a throttle oil passage 222 with the oil passage area smaller than that of the normal oil passage 221. When a D range is selected from an N or P range by a shift lever 260, the throttle oil passage 222 of the change-over valve 220 is selected, so as to raise the hydraulic pressure applied to the advance clutch 27 slowly. Consequently, the shift shock is reduced. And since an operation oil can be fed to the advance clutch 27, even though either oil passage of the changover valve 220 is selected in the D range, the forward running in the D range can be secured. |
